Shortly afterward, the Thai government said it had arrested a Lebanese man and described him as a member of the militant group Hezbollah. Thailand’s deputy prime minister told news agencies that the arrest came after days of coordination with Israel that began with a tipoff in late December.
“Following concern raised by the Israeli Embassy about a possible attack by a group of Lebanese terrorists in Bangkok, Thai police officials had been coordinating with Israeli officials since before the New Year,” the deputy prime minister, Chalerm Yubamrung, told Reuters.
It was not immediately clear whether the warning by the United States and the arrest were connected.
The embassy alert, addressed to American citizens, said that “foreign terrorists may be currently looking to conduct attacks against tourist areas in Bangkok in the near future” and urged “caution when visiting public areas where large groups of Western tourists gather in Bangkok.”
Tourism is one of Thailand’s major industries, and millions of foreign visitors visit the capital each year, according to Thai government statistics.
Mr. Chalerm stated that the authorities had been tracking two men but that they had only arrested one, who was being held in connection with possible immigration violations. “Technically the two men have not committed any crimes under the Thai law, so we could only use the immigration law to keep this one suspect in custody.